The Sangheili[7] (Latin Macto cognatus,[8] meaning "I glorify my kin") are a saurian[9] species of fierce, proud, strong, agile and intelligent warriors. Named after their home planet, Sanghelios, they are known to humans as Elites[10] for their adeptness and skill in military strategy. The Sangheili formed the military backbone of the Covenant until just before the end of its existence. They had a very strong rivalry with the Jiralhanae, which finally led to open conflict during the Great Schism at the conclusion of the Human-Covenant War.

Originally a founding species of the unified conglomerate of races known as the Covenant, they later led the initial Covenant breakaway faction, the Swords of Sanghelios, who sided with the humans against their former allies, due to the fact that the High Prophet of Truth and the High Prophet of Mercy had ordered the genocide of the entire Sangheili race. This was established after the assassination of the High Prophet of Regret at the hands of John-117. It was the Sangheili who were ultimately held responsible for the Prophet of Regret's death, and were seen as "unfit" to continue to guard the Prophets. The Prophets sought to achieve this through the use of the other Covenant races, primarily the Jiralhanae. The aftermath of the Great Schism formed the bedrock of the Covenant's ultimate collapse.

The Sangheili evolved in tropical wetlands of their homeworld, Sanghelios.[11] Sanghelios had at one point been visited by or had been in contact with the Forerunners. During the Forerunner-Flood war, the Librarian visited the planet to retrieve specimens of the Sangheili for preservation aboard Installation 00. After the firing of the Halo Array, they were returned to their home planet to begin rebuilding their culture.[12]

After being returned to their homeworld, the Sangheili discovered artifacts left by the Forerunners on their planet. The Sangheili revered the objects these "gods" had left, and considered tampering with them a heresy beyond any other. However, some Sangheili scientists defied their species' dogma and studied Forerunner artifacts in secret; they would later become instrumental in helping the Sangheili reverse-engineer weapons against the San'Shyuum.[13] Several hundred years prior to the formation of the Covenant, the Sangheili had developed slipspace technology and created dozens of independent colonies, though their homeworld of Sanghelios remaining central to governance and culture. The planet of Creck, discovered before the Sangheili's contact with the San'Shyuum was the seventy-sixth of designated worlds explored by Sangheili. At some point, an unknown number of Sangheili clans waged war upon each other for numerous years on Sanghelios. These engagements became known as the Clan Battles of Sanghelios.[11]

In 938 BCE the Sangheili encountered the ReformistSan'Shyuum, a race who also worshiped the Forerunners as gods, but had utilized Forerunner technology for their own needs, believing the technology had been left behind by the gods as gifts for their children.[14] This sparked a war between the two races over how to treat the relics. Even though the Sangheili were much more physically imposing and numerous, they suffered extreme casualties under the sheer power of the San'Shyuum's Dreadnought, a surviving Keyship, and by 876 BCE even the most devout had to admit their survival depended on the reconstitution of their own Forerunner technology. This led both sides to an agreement that ended with the decommissioning of the Forerunner Dreadnought and a shaky alliance that eventually expanded into the Covenant.

The San'Shyuum helped assuage the Sangheili by informing them of the Great Journey: by seeking out the Holy Rings scattered throughout the galaxy and utilizing them, a "Great Journey" would transform believers into godlike beings. The Writ of Union was drawn up in 852 BCE in order to codify the Covenant. Its first canto clearly outlines the nature of the Covenant from the perspective of the Prophets.

Being one of the few races in the Covenant to achieve space-faring status without outside intervention, Sangheili interaction with the San'Shyuum was initially strained due to memories of the recent war. Many Sangheili felt that the Writ of Union meant surrender to the San'Shyuum, although most never voiced these concerns.[15] The Sangheili Ussa 'Xellus led a major rebellion against the Covenant that was eventually neutralized with the rebel Ussans going into hiding.[16] Over time, the San'Shyuum and Sangheili formed a prosperous relationship, eventually laying the foundation for the modern Covenant hegemony.

During their membership in the Covenant, the Sangheili were simply put, technological and societal equals of the San'Shyuum. However, for a significant period, they found themselves as the dominant military muscle for the entire Covenant structure - hardly surprising given the warlike, feudal nature of their homeworld. What was surprising was the cyclical stability this feudal society was able to offer. Technological and medical advancement prospered, and the intelligent, aggressive Sangheili were peerless until they encountered the San'Shyuum. With exchange of goods and ideas, the Sangheili adapted to and eventually embraced the Covenant religion, grafting its tenets to their own belief system.[8]

When the Prophets declared war on a previously unknown species called humans, the Sangheili followed their lead without question. After a period of time, however, even though the Prophets insisted that the humans were "unclean beings" that must be eliminated from the galaxy, some seasoned Sangheili veterans began to question the refusal of the Prophets to even consider accepting the humans into the Covenant. They seem to believe that humans, although physically weak, at least compared to themselves, are brave and even honorable. As such, these few Sangheili believed that humans should be offered admittance to the Covenant.[17] Some even believed that the humans are equal to them - a considerable step for a Sangheili, or any member of the Covenant to make. These Sangheili admired how willing and brave the humans were when fighting to survive against outright extinction, they even respected to a certain degree those few soldiers who were willing to stay behind and cover their comrades from a Covenant attack. A few Sangheili even had more respect for the humans than they did for the San'Shyuum before the Great Schism.

These events led the entire Sangheili species to secede from the Covenant, forming a faction of separatists later to be known as the Swords of Sanghelios. They were aided by a few of the member races within the Covenant, such as many Unggoy and most Mgalekgolo, although many sided with the High Prophets despite the Sangheili's efforts. The secession included a movement to destroy the treacherous Jiralhanae and High Prophets, and the destruction of the Flood at all costs, eventually resulting in an alliance between the Arbiter's forces and humanity.

The Great Schism stretched from the human homeworld, Earth, all the way back to Sanghelios as the Sangheili attempted to wrest their share of the hegemony away from their new-found enemies. The Jiralhanae stepped in to fill the military void in ever increasing numbers, sensing the vacuum and opportunity left by the departure of the Sangheili.

After the Battle of Earth, the Sangheili and humans managed to stop and subsequently kill the Prophet of Truth, effectively dissolving the Covenant. However, the Sangheili and humans were coerced to deal with a more massive threat; the Flood. Finally, the Arbiter and the Master Chief, after activating the newly constructed replacement Halo ring, effectively ended the Flood threat.

Following the destruction of the Covenant, Sangheili society plunged into crisis. Already lacking centralized governance and splintered to independent city-states spread across several dozen major colonies,[18] they fractured into multiple infighting factions with varying ideas on how to run their society, despite their ongoing war with the Jiralhanae. This was largely due to the fact they had become reliant of the Prophets during the millennia of the Covenant's existence. As they regained their independence, they were forced to re-learn to manage their society on their own, without the direction of the Prophets or the manual labor provided by the other client races.[19] One faction, the Servants of the Abiding Truth, opposed Thel 'Vadam and his allies, specifically their rejection of the notion of the Forerunners being gods.[20]

As the Great Schism went on, the Sangheili continued their fight against the Jiralhanae. This was proving largely unsuccessful and the Sangheili were accepting serious losses. Without the Covenant to provide them with ships, technology, and repairs, they slowly lost warships and technologies they couldn't repair or replace. After the San'Shyuum went into hiding, the Sangheili began to prevail against the Jiralhanae, who in turn began to fight amongst themselves. Having abandoned the Covenant, the Sangheili were now in a state of mass confusion in regards to their religion, because even though the San'Shyuum lied to them, they had still given them purpose for their actions. Many Sangheili were still religiously devoted to the Forerunners and were attempting to uncover the meaning of their faith.[21]

After the Human-Covenant War, there was competition between the UNSC and the Sangheili, when it came to examining Forerunner ruins and relics like the Portal at Voi.[22] By March 2553, a tentative ceasefire continued to exist between humanity and the Sangheili. Although Arbiter Thel 'Vadam campaigned for peace between the two species across various Sangheili states, many Sangheili continued to view humans with suspicion, perceiving them as a threat and wanting to destroy them once and for all. At the same time, the UNSC's Office of Naval Intelligence took advantage of the unstable political situation, attempting to keep the Sangheili splintered and disorganized by inciting the Servants of the Abiding Truth to rebel against 'Vadam. This was to make sure the Sangheili would not pose a threat to humanity again, in spite of the UNSC's alliance with the Arbiter's faction.[23]

ONI's aid allowed the Servants of the Abiding Truth to amass enough weapons to begin an all-out insurrection against 'Vadam and his allies in early 2553. Meanwhile, however, ONI's efforts also backfired; partially as a result of their actions the Sangheili Jul 'Mdama began a personal quest against humanity, forming a Sangheili-led reconstituted Covenant mainly from ex-Covenant forces. Four years after the battle at the Ark, this group launched an invasion on the Forerunnershield worldRequiem, intending to find and awaken the Didact, a Forerunner Promethean they revered as a living god.

In spite of ONI's underhanded mission, relations between humanity and Sangheili at large continued to be amicable. For example, the UNSC and the Sangheili under the Arbiter maintained mixed control over certain space territories, known as Joint Occupation Zones. The UNSC Navy and the Sangheili also participated in joint naval operations, including one against pirates in 2557.[24] Human and Sangheili scholars also gathered and studied the Covenant's records together on Sanghelios.[25] Collaborative weapons research (such as the study of the physics behind the Type-33 Needler) and exchanges in military intelligence between the two species is also known to have taken place.[26] In addition, a select number of Sangheili are known to have been offered the opportunity to train alongside Spartan-IVs in War Games simulations as part of the ANVIL initiative.[27] A notable example of trust and technological exchange between humanity and Sangheili is the Helioskrill armor, a variant of MJOLNIR Powered Assault Armor, one of the most sophisticated pieces of human technology, which was designed by a Sangheili prodigy and manufactured by the Kolaar Manufactorum, a forge based on Sanghelios.[28] On the other hand, not all humans were amicable towards coexistence with the Sangheili, as seen with the Sapien Sunrise. In one notable incident, nine members from the aforementioned terrorist organization infiltrated Richard Sekibo's delegation at a peace summit on the colony world of Biko. They intended to assassinate Sekibo and a Sangheili delegation while framing the Sangheili of the crime. The assassination attempt was foiled by Spartan John-117 though Sekibo was mortally wounded. Unfortunately, the truth was covered up and John-117 was used as a scapegoat to hide the UEG's laxity towards preventing the attack, much to the frustration of the Sangheili delegation.

In one notable incident, the Office of Naval Intelligence deployed three prowlers to trail the allied Sangheili assault carrier Shadow of Intent. All three stealth vessels were reported destroyed under unclear circumstances; the losses were not reported to UNSC Naval authorities.[24] Despite this, the alliance between the Arbiter and humanity continued to hold. On March 5, 2558, 'Vadam accepted the UNSC as mediators to oversee his peace negotiations with the Jiralhanae ChieftainLydus.[29]

During the crisis that followed the dissolution of the Covenant, some Sangheili sought asylum on Earth. In 2558, at least one settlement of former-Covenant races was based in the South American city of Rio de Janeiro.[30]

Sangheili are physically imposing beings, typically standing more than a foot taller than the average human. They are vaguely reptilian in overall appearance, with leathery skin, reverse-jointed legs and sharp claws and teeth. Their large hands have two fingers and two thumbs. Their most unique trait is their jaw structure, which is made up of four separate mandibles attached to their face.

The Sangheili are known for great strength and intelligence, and are praised for their bravery and honor. Sangheili warriors augment these natural abilities further through use of energy shields integrated into their armor. Depending upon rank and mission objective, they are commonly seen in battle with plasma rifles, carbines, Needlers, needle rifles, and sometimes energy swords. Sangheili employ coffin-like orbital insertion pods as well as Spirit and Phantom dropships for military transit purposes and rapid-response operations.

Historically, Sangheili have followed the Covenant mentality of maintaining hatred towards humanity, believing them to be an affront to their religion and a challenge towards the Great Journey. However, many Sangheili were able to put this animosity aside when an alliance of Sangheili-led separatists joined the UNSC during their expedition to the Ark. After the Human-Covenant War, many Sangheili are still distrustful of humanity and some still wage war against them. Nonetheless a large number of Sangheili, most notably those loyal to Thel 'Vadam, have attempted to form steady alliances with their former enemies.

Sangheili are muscular and very tall, usually standing between 2.25 and 2.62 meters.[1][2] Their jaws are quadruple-hinged, with an upper jaw and four lower mandibles arranged in two tiers. Mandible and upper jaw structure along with teeth shape and numbers result from different phenotypes; however they do not indicate reproductive isolation.[31] These mandibles have between six and twelve teeth each and some Sangheili have an additional, larger fang on the tips of each mandible.[32][33] Anywhere from eight to more than a dozen broader teeth may be mounted on the upper jaw structure. Adult Sangheili mandibles can be found in varying shapes, sizes, and ranges of dexterity, and are as distinctive as a human fingerprint.[34] Some Sangheili also possess molars. Sangheili smell with the use of two nostrils, each slightly in front of and below the eye socket. Given their predatory nature, a Sangheili's sense of smell is likely very developed.

Their hands are tetradactyl, each having two fingers in the middle and an opposing thumb on either side. Their legs are digitigrade, with short upper and lower legs, and elongated tarsals, using the distal and intermediate phalanges to support their weight when walking. This arrangement possibly allows them to run very quickly and jump large distances, compared to ordinary humans and other Covenant races.[35] Their superior agility may also be attributed to their homeworld's higher gravity; the additional strength required to move normally in a high-gravity environment would likely cause them to be more powerful in lower gravity situations (though, curiously, their tall, large, and lean figure would be extremely disadvantageous and impractical on a high-gravity planet—an arrangement possibly allowed by other major factors in their biology and life cycles; alternatively, the impressive strength and agility may be the result of the capabilities of their standard-issue combat harnesses). They also appear to have a double set of pectoral muscles, which contributes to their incredible strength. On the other hand, their digitigrade stance makes it difficult for them to climb vertical constructs such as ladders.[36]

A close-up of a Sangheili's face, showing the jaws which have earned nicknames such as "Split-lip" and "Squid-head"

Sangheili have a binary circulatory system[37][38] that pumps indigo-colored blood. They breathe oxygen and their homeworld has a nitrogen-oxygen atmosphere comparable to Earth's, allowing them to breathe the same atmosphere as humans. Sangheili cannot breathe molecular nitrogen.[39]
Sangheili possess a cloaca, which is a common orifice for the digestive, reproductive and urinary tracts.[40]

Most Sangheili have leathery skin covered in many part by scales. The skin's colour can range from light brown to dark brown and from light gray to black. They have forward-facing eyes with vertical slits and horizontal eyelids much like those of terrestrial reptiles,[41][42][note 1] likely giving them high-resolution central vision and depth perception. Sangheili are unable to perceive purple tones, which they see as blue. They are also able to see in the "infrabrown range". This apparently indicates that they lack L cone cells.[43] Their eyes can have multiple colours ranging from red all the way to green and can be even gray. Most Sangheili though possess yellow or orange eyes.[note 2][note 3]

Sangheili exhibit minor sexual dimorphism, with the females being slightly smaller than the males.[44] Sangheili males possess a subtle leathery scent, while females have been described as smelling like "clean feathers".[45] Sangheili are oviparous, meaning that they lay eggs rather than giving live birth.[46] They incubate their recently hatched young in tank-like pods.[47] The species is remarkably long-lived; Sangheili over 60 or 70 years of age have shown to be fully fit for combat duty,[48][49] and Jul 'Mdama was considered young, at least in keep elder terms,[50] at 64 years old.[51] Circa 100,000 BCE Sangheili life expectancy was 27 Earth years.[46][52]

An example of Sangheili's mentality of being a superior species; here, Thel 'Vadamee defies a Jiralhanae to handle him after a trial.

The Sangheili consider most other species to be inferior to them, both culturally and in fighting skill; this thinking has caused Sangheili to treat other species cruelly and in an arrogant manner. This eventually led to the feud between the Sangheili and Jiralhanae. Although Sangheili are naturally very intelligent, their culture's long dependence on a military-industrial scheme has led to an emphasis on might over science. In some regards, the advent of the Covenant made this position easier-allowing the Sangheili to concentrate even more mono-manically on military endeavors, while Prophets took care of science and technology.[8] Despite this, their adeptness at using and creating technology is evident. It is probable that they designed many of the Covenant's warship types themselves. They demonstrated their superiority at space combat in the battle with the Jiralhanae over Installation 00.

Promotion in the Covenant military is by merit. A Covenant soldier must succeed to advance among the ranks, with this success being measured in combat kills. A Sangheili near the top of the military hierarchy may have personally slaughtered thousands of individuals to reach that status.[53] This practice sometimes puts individuals of questionable strategic acumen in positions of command. In the case of Ripa 'Moramee, a particularly brutish Sangheili was appointed as Arbiter, both for his martial ability and for his unquestioning obedience to the Prophets.

Raised from childhood to be warriors, other societal roles are treated as secondary endeavors or even hobbies. Doctors are considered outright dishonorable as they "spill blood" outside the battlefield;[54] despite this, the Sangheili are known to employ advanced medical technology[8] that is superior to humanity's.[55] Few doctors exist within Sangheili society. Instead, Huragok and other species are employed as medical personnel. Most injuries sustained by the Sangheili can easily be treated by the medical technology employed by the species, otherwise they accept their fate. However, Sangheili hold disdain for using medical technology to treat themselves and some personally would rather suffer through their injury or die. Sangheili recognize that other species do not share the same views on medical treatment and were willing to lend them their medical technologies or even treat the wounded individual themselves.[56] Elites are very skilled in most ranged weapons, as well as hand-to-hand combat. A prominent example of this martial focus is that only aristocrats are allowed to wield energy swords and that sword-wielders are then no longer eligible for marriage; however, they may breed with any female they choose, married or otherwise, to ensure successful transmission of "swordsman" genes. Many Sangheili children are trained in basic swordsmanship early on, both for personal development and for them to be capable of using a sword later in life if necessary. Within the military, an aristocratic title is not necessary for wielding an energy sword.[57]

As a symbolic gesture of love for his people, a Sangheili leader may walk among his followers and help them in their duties, even doing what is normally considered females' work such as helping them care for eggs. This is also done to inspire the Sangheili to work diligently so as to not be outdone by their superiors.[58]

The Sangheili display respect and admiration for honorable fighters, whether they are allies of the Sangheili or not; it is not unusual for the Sangheili to have such an admiration for their adversaries. Sangheili respect and revere veterans and often follow their lead. Their history is rife with victorious combatants welcoming the defeated enemies' remaining forces into their own army, provided of course that they fought with honor. During the Unggoy Rebellion, the most tenacious of the Unggoy who survived the conflict were admitted for the first time into previously all-Sangheili forces, much to the Prophets' discontent.[60]

Despite their intelligence, the Sangheili often allow their obsession with honor to cloud their better judgement. The Sangheili usually employ complex strategy only if it either improves success in battle, allows them to inflict more casualties on their enemies, or if it conforms to their code of honor. Otherwise, in both tactical and strategic combat, Sangheili generally charge their enemies with reckless aggression, regardless of any damage they sustain. Only very seldom do they admit temporary defeat, while lower-ranked Sangheili might make numerous tactical mistakes, such as standing in the open rather than taking cover. More experienced Sangheili are notorious for luring their enemies into traps and quickly dispatching them in close combat. Sangheili often sustain heavy casualties in the fervor to kill, though they use their client races to screen and protect themselves. The race's desire for grandeur has led to their defeat in many engagements, such as the Battle of Psi Serpentis, Operation: FIRST STRIKE, and the Battle of Onyx.

Conversely, those who favor practicality over religious fervor in combat exhibit keen tactical and strategic acumen. The Zealots, despite being among the most fervent adherents of the Covenant's religion, use shrewd, pragmatic tactics and are willing to engage in subterfuge in lieu of open combat. Similarly, special operators and stealth specialists use active camouflage even in combat, though most would prefer to fight outright than to skulk in shadow. The separatist Fleet of Retribution destroyed the Prophet of Truth's fleet, despite the latter outnumbering the former three-to-one. Some Sangheili, such as Jul 'Mdama, see honor as more of an aspiration than a way of life and are willing to engage in deception if need be, particularly after seeing humans use such tactics to great effect.[61]

The Sangheili code of honor appears quite similar to Japanese Bushido, sharing concepts such as skill in combat (with an emphasis on swordsmanship), loyalty to master and family/clan, and views on death. Both systems promote death in battle as being the most honorable and proper way to die. If a warrior is critically injured, incapacitated, or captured, the only acceptable recourse is to commit ritualistic suicide, ensuring one's honor is kept intact. This is of such importance to Sangheili warriors that even if they are incapable of killing themselves, they may request the assistance of their fellow Sangheili in doing so.[62] The Sangheili consider being captured in combat to be dishonorable. To retain his honor, a valiant Sangheili would typically commit suicide while in prison. Often when imprisoned Sangheili are freed those who have not killed themselves are executed anyway, as was the case with one of Thel 'Vadam's ancestors. However, escaping or staging an uprising is acceptable, by the same example.[63]

Despite their martial nature, the Sangheili have reservations to the spilling of one's own blood. This is an extension of the belief that the blood of a warrior is his essence, which is synonymous with his honor; thus, to spill one's blood is to lose one's honor.[54] As a result, in Sangheili culture, doctors are seen by many as the lowest members of society because they "..make [their] living slicing and causing another Sangheili to bleed without honor."[54] This means that the only 'honorable' way for a Sangheili to be injured or bleed out is from combat with the enemy. This belief also makes visiting a doctor very shameful for some Sangheili.

Many Sangheili believe that a weapon is to be drawn only if it is to be used, because a drawn weapon "demands blood."[64]

The Sangheili have no unified government; they are splintered into numerous feudal,[65] meritocratic states.[66] A given state is governed by a single clan residence and assembly house known as a keep, headed by a kaidon selected by a council of elders. There are usually a number of "client keeps" belonging to different clans under the leading keep's rule,[67] though a state's elders will assume the kaidon's clan name as a title signifying their position, regardless of the name of their own family keep.[68] Sanghelios was once governed by the Council of City States during the early history of the Covenant.[11]

In Sangheili culture, it is customary to settle disagreements with authority by assassination, though one has to use personal weapons in order for the practice to be considered honorable.[69] For example, if a council elder believes that his vote was ill-advised or had second thoughts, it is considered a tradition for council elders to initiate some form of attack, such as sending assassins, against the kaidon in order "...to test the true merit of [the] ruler's martial abilities."[66] The belief was that "a kaidon who could not defend himself was not a true leader."[54] Should the attack fail, the responsible elder will be executed immediately, and his family will be killed. However, punishment for this form of heresy was usually flexible. As such, if the elder did something honorable, such as attack the kaidon himself, or attempted to make a final stand against the kaidon, then he would probably have managed to save his family from certain death, although they might still be banished.

Family history and lineage are greatly valued, with each family having their own unique "battle poem" detailing the deeds and actions of its members during times of war.

Although Sangheili society is classified as being patriarchal,[8] and while most males serve as warriors, female Sangheili hold considerable power in issues within their family keeps, including political matters, civil duties and trade, while Sangheili males are sent into service as warriors. Sangheili believe that copulation without regard for the bloodline is uncultured, but only the females have access to records of their own bloodlines, and are able to choose their mates.[70] The maintaining of a clan's familial records is typically the duty of the wife of the keep elder.[71] The concept of divorce is completely foreign to Sangheili.[72]

Sangheili warriors form very close-knitted relationships, referring to their comrades as "brothers" and remaining intensely loyal to them. This loyalty is shown in the custom of grieving after the death of a fallen comrade, a ritual which includes prayer for the dead warrior.

Newly hatched Sangheili are called "childlings", and as they grow older, they are then referred to as "younglings".[73] Sangheili children are typically raised in the communal environment of their family keep to ensure that all start on an equal footing and progress in rank by merit of their abilities. They are not allowed to know the identity of their true fathers and are usually raised by a maternal uncle instead. This is a method of preventing status from being inherited in order to force children to make their own way in the world so they actively work for and earn advancement,[74] thus minimizing nepotism. However, as some children's fathers were swordsmen who were granted the right to reproduce with any number of female Sangheili they desire, the use of a maternal uncle as a father-like figure is used to allow children to be raised equally.[8] Sometimes the individual acting as a Sangheili's "uncle" is in fact the father, but this makes no difference to his role as the child will never know.[75]

Ussan Sangheili do know who their fathers are, presumably because they wanted to be sure who was descended from legendary figures such as Ussa 'Xellus and Ernicka the Scar-Maker and to possibly avoid inbreeding given their limited numbers.

Both male and female Sangheili are taught to fight from a young age. Though only males go on to become warriors, it is believed that the females should be able to defend themselves in the event their keep is attacked.[76] A popular pastime for Sangheili children is to hunt small rat-like creatures that live on their homeworld.[77]

The Sangheili language, which served as a lingua franca to the Covenant, is rather harsh and guttural to human ears. While much remains unknown about its overall structure and conventions, it is known that certain sounds are largely absent from the Sangheili language due to their unique mouth structure; for example, Sangheili have difficulty pronouncing human words containing the letter "v" or ending with "p", resulting in the name "Evan Phillips" (As in Dr. Evan Phillips, a scholar of the Sangheili language) being pronounced as "Efanphilliss" (however, there are names in the Sangheili language that use these letters, such as "Vadam" and "Ripa").

Certain Sangheili colloquial terms have been translated by human linguists; the majority of these are derogatory in nature. The word "Jir'a'ul" is a term of abuse for Jiralhanae, being a portmanteau of the name "Jiralhanae" and the word "a'ul," the Sangheili word for a lump of wood.[78] The Sangheili often refer to humans using the word "nishum," which translates roughly to "worm" or "intestinal parasite." The origin of this term lies with the first encounters between Sangheili soldiers and human military personnel. Upon first sighting human infantry, the Sangheili mistook their body armor for an exoskeletal shell. After examining dead human soldiers, the Sangheili discovered the relatively weak, fleshy creatures underneath the "shells" and came to the conclusion that they were some sort of internal parasite. Even long after this misconception faded, the term remained in use among the Sangheili as an unflattering insult to their human enemies.[79]

The Sangheili place great value in names and titles, and consider names to be a privilege given only to those who are worthy. The Sangheili generally regard humans as nameless, aside from generic labels, such as "Demon" (a term used to refer to Spartans). They resent that the humans have assigned the label "Elite" to them (along with many other, far more derogatory names, such as Squid-head, Split Lip, etc).

A Sangheili's first name is a given name that is attained at birth and persists throughout adulthood. It is followed by a family name, which denotes their lineage. Thel 'Vadam, for example, was from the Vadam lineage. Some lineages, such as Vadam, have control over their own states,[65] although this is not always the case; it is typical for Sangheili of other lineages to occupy smaller keeps in a state named after another lineage. Client keep elders within a given state typically adopt the name of the state instead of using their own family name.[47][67] Family names may carry a suffix such as "-ee" (an honorific indicating that the Sangheili has enlisted in the Covenant military). Since the Great Schism, most Sangheili have dropped the '-ee' suffix.[80] Additional titles, such as "Jar" and "Nar," appear to be related to specific ranks (Imperial Admiral and Fleet Master, respectively). Apart from the "-ee" suffix, the suffix "-ai" denotes swordsmanship, as with Bero 'Kusovai and Toha 'Sumai.[81]

The apostrophe in front of the clan name indicates a sound resembling a glottal stop or click.[82]

Sanghelios is the homeworld of the Sangheili species with a population of 8.135 billion as of 2552.[8] Sanghelios is the fourth planet in a triple star system of stars Urs, Fied, and Joori. The planet has two moons called Qikost and Suban.[8]

As a space-faring species, the Sangheili have colonised multiple planetary entities as they ventured space, first expanding the reach of their own civilization and later that of the Covenant empire. There are several dozen worlds considered as major centers of their civilization. Like their homeworld, the colonies house a number of independent city-states as opposed to a unified government.[18]Joyous Exultation was a significant nexus of Sangheili military during the Covenant hegemony's reign, while Hesduros is an example of a more remote Sangheili colony.

The title of Arbiter was originally granted to the warrior ruler of the Sangheili clans,[84] and was considered a great privilege.[85] However the conflict caused by Fal 'Chavamee in his refusal of the Covenant religion, had led the Prophets to significantly repurpose the role. In times of an extraordinary crisis, it would be reserved for the most disgraced Sangheili and offered as a means to regain their honor through suicidal missions of great importance to the Covenant.[86] It also served as a convenient means for the San'Shyuum to silence Sangheili in positions of power who may have started to question the Covenant religion or the Prophets' rule.[84]

As part of the Covenant Honor Guard of the old Covenant empire, the Honor Guardsmen were highly skilled warriors, hand-picked for the duty of protecting members of the High Council and the Hierarchs.[87][88] Although it was a great honor and they were expected to eliminate anyone who drew a weapon in the presence of a Hierarch,[89] the position was seen by some Sangheili as merely a ceremonial duty too removed from battle. One of the most formidable groups in the Honor Guard is the Light of Sanghelios.[90]

In Sangheili culture, it is customary to promote individuals based upon their skills, abilities, and the number of casualties they inflict upon their enemy.[10] In the original Covenant, a fresh Sangheili recruit would start as a Minor (indicated by their blue-colored armor), and later promoted as a Major (indicated by their red/crimson-colored armor) when he has acquired sufficient experience in the field. Both Minor and Major are capable of leading up to three lances of Unggoy and Kig-Yar.

They can continue to be promoted to an Ultra, serving as field officers.[91] Whilst they often engage in open battle,[92] commanding multiple squads of Sangheili, Unggoy and Kig-Yar, they are sometimes deployed alone on high-priority missions such as the command of Scarab assault platforms.[93] A further advancement in the ranks is the rank of a General. They have been observed personally leading both warships and infantry on the battlefield.[94] Whilst they can lead anywhere between hundreds to thousands of soldiers alone, when multiple Generals are required, they will fight in concert to resolve battles.[95][96]

One of the highest ranks attainable by a Sangheili, an Imperial Admiral bestows the control of large combined fleets and operate on powerful capital warships, such as an assault carrier or supercarrier. Rather than require groundside combat proficiency, they are requested to be tactically excellent and to hold a great influence over the vastly numerous troops within their command. The only known Imperial Admiral is Xytan 'Jar Wattinree.[97]

The rank structure in Jul 'Mdama's new Covenant retains much of the structure of the Covenant hegemony: Sangheili are given ranks according to their experiences in combat as well as to their particular skills and abilities. A fresh Sangheili within this unified Covenant starts as a Storm unit (indicated by their blue-colored armor) and would be promoted as a Commander (indicated by their red/crimson-colored armor) when he has gained sufficient field experience. Those that served the old Covenant empire, having obtained decades of experience in the Human-Covenant War, would also be classified as Commanders.

Seasoned veteran Sangheili who survived the Human-Covenant War are classified as Warriors. They are considered some of the most fearsome members in the new Covenant order.

Shipmaster: Reserved for Sangheili commander of individual ships, though they sometimes command small task forces, as well. The term "Shipmaster" is not exclusive to Sangheili, and is universally used by the Covenant to refer to an individual of any species in command of a starship.

Fleet Master: Given to a high-ranking Sangheili in command of a fleet.

Supreme Commander: The Covenant's equivalent of the human "Commander-in-Chief". The most well known Supreme Commander was Thel 'Vadam, who commanded three fleets during the Fall of Reach, while serving as fleetmaster of his own Fleet of Particular Justice, which he took to Installation 04.

Managed under the Ministry of Fervent Intercession, the Zealots are a specialized group of Sangheili tasked with the search and recovery of Forerunner artifacts.[98] They are involved in deep-infiltration, high-risk operations, sometimes led by a Field Marshal. In addition to artifact retrieval, the Zealots can also serve in other command roles.

In the new Covenant order led by Jul 'Mdama, much of the Zealots originate from Hesduros.

Part of Covenant's Fleet Security, the Rangers are a group of Sangheili specializing in zero-gravity, exoatmospheric environment and extra-vehicular space combat.[99] Their suits provide a great degree of mobility in such extreme environment.

The Fleet Security's cover units are the Stealth Sangheili. Their role focuses on acquisition of intelligence and strategic countermeasures than direct combat. Like the Special Operations, they utilize active camouflage in their operation. The Ossoona, or "Eyes of the Prophets", is a subset that operates under the Stealth Sangheili for the purposes of information gathering on enemy weapons and military data.

After the collapse of the old Covenant empire, the role of Rangers persists in the Covenant remnant faction led by Jul 'Mdama.

The Special Operations is the Special Warfare Group's division for unconventional warfare.[100] Comparable to Zealots, the Special Operations are tasked with suppressing enemy progression and disable enemy installations. The division is controlled by the Special Operations Commander.

Special Operations Sangheili operate in small squads and boast superior shielding system and active camouflage. They are often led by Special Operations Officers and supported by Special Operations Unggoy.

The Ascetics are a special group of Sangheili devoted to ensuring stability and purity within Covenant society.[101] At the formation of the Covenant, the Writ of Union termed the dissolution of their order. Instead, they were reconstituted as an organization under the Ministry of Abnegation. The wake of the Great Schism brought the return of the Ascetics as an independent group.[102]

The dialogue spoken by the Sangheili of Halo: Combat Evolved was made by reversing and slowing sound clips of Sergeant Johnson. "Wort! Wort! Wort!" is the reversed phrase, "Go! Go! Go!". With the IWHBYD Skull turned on in Halo 3, they will occasionally say their trademark, "Wort! Wort! Wort!".[citation needed]

Jason Jones at first wanted the Sangheili to have tails, but Shi Kai Wang talked him out of it by arguing that the Sangheili would look too animalistic, as opposed to being an intelligent race. An additional point was that when the Sangheili sit, the only place their tails could go was folded between their legs, creating a seriously awkward appearance.[103]

Over the course of development for Halo Wars, the Sangheili character model used in the cinematics went through at least two revisions. The initial version seen in the announcement trailer was later revised, being far closer in size, proportion, and overall physiology to the portrayal of the species in Bungie's games than the version in the trailer.

In The Duel the Sangheili Han, Fal, and Roh keep their mandibles closed, using only the front two joints of their lower mandibles to speak, giving them a more humanoid appearance. This is an example of artistic license intended to humanize the protagonist and those close to him.

In most games the Legendary symbol features a Sangheili skull with a bullet hole through the left temple. In Halo 3: ODST the skull is a human's, while in Halo 4 it belongs to a Promethean Knight.

The Elites are the first Covenant species the player encounters in most of the Halo games: while heading to the Pillar of Autumn's bridge in Halo: Combat Evolved; at Thel 'Vadamee's trial in Halo 2; in the opening cutscenes of Halo 3 and Halo Wars; and in the prologue cutscene of Halo 4, as well as the first level of gameplay. In Halo: Reach a camouflaged Elite can be found at the beginning of the level Winter Contingency, though only on the Legendary difficulty.

According to the original edition of Halo: The Fall of Reach, Elites had not been deployed in combat against the UNSC prior to the Fall of Reach when John-117 encountered one above Reach, a claim ignored in subsequent media.[104] The 2010 reprint of The Fall of Reach removes all references to the Elites being a yet-unencountered species.

Although the player is not able to dual wield in Halo: Reach, Elites are occasionally seen dual wielding plasma rifles.

In Halo: Reach, the Sangheili HUD compass has Covenant markings instead of cardinal directions. Sangheili night vision is also purple, as opposed to the green used by Spartans. However, Sangheili night vision is only available in Firefight Versus, when playing as Elites. The Sangheili HUD also features a target tracking system.

^In most of their pre-Halo 4 depictions, the Sangheili have slightly laterally-oriented eyes. The Sangheili featured in Halo 4 and later media have more forward-facing eyes befitting a predatory species.

^In Halo 2 Thel 'Vadamee has magenta eyes and Rtas 'Vadumee has green eyes. In Halo 3 and Halo 2: Anniversary they, like all other members of their species, have orange-yellow eyes. A Sangheili Zealot seen in Halo 4: Forward Unto Dawn also has yellowish green eyes, Gek 'Lhar has yellow eyes, Jul and Rho have grey eyes and Vata 'Gajat from Halo: Escalation has red eyes. While 'Vadamee's and 'Vadumee's eye color was clearly retconned, the latter examples could be instances of artistic license, though they may instead indicate that other eye colors are exhibited throughout the species.

^Sangheili NPCs in Halo: Combat Evolved wear eye coverings corresponding to the color of their armor, while Elites of all ranks wear black lenses in Halo 2. These devices were likely meant to project the combatant's heads-up display. However, these coverings have not been seen in any media since Halo 2; Halo: Combat Evolved Anniversary and Halo 2 Anniversary instead depict all Sangheili with uncovered eyes.

^Twitter: JoshingtonState (@JoshingtonState: "Little known fact, Elites are all color blind (like @franklez). This whole time they thought they were using BLUE! ;)") ("@JoshingtonState: "Frank says "infrabrown range" - not sure exactly what this means.")